textproduct: Quad Cities

KEY MESSAGES

- Today and Thursday will see severe storms that may be widespread. There in an Enhanced, level 3 out of 5, risk for severe storms each day. There continues to be a signal suggesting two rounds of storms each day. The second round each day could extend into the evening hours.

- On both days, the initial development of discrete storms will be capable of producing very large hail and tornadoes. Once storms develop into a line, damaging winds, potentially over 70 mph, and spin-up tornadoes will become the main risks.

- Storms Today and Thursday will be very efficient in producing heavy rainfall. Heavy rain today may set the stage for potential flash flooding with the storms on Thursday.

SHORT TERM /THROUGH THURSDAY NIGHT/

Issued at 219 AM CDT Wed Jun 10 2026

Heat and humidity will be seen across the area today with peak heat indices in the mid to upper 90s. Cloud cover could lower temperatures and afternoon heat indices.

Outside of the heat, the next 48 hours will be very interesting.

The very short term models continue to signal the potential for two separate rounds of strong to severe storms. There may only be a few hours in between each round of storms.

Wednesday/Wednesday night...

The first round of storms is now looking to occur in the 10 AM to 4 PM across the area and likely associated with the upper level disturbance coming out of Kansas. Round two looks occur 3 to 10 PM and looks to be a combination of differential heating and another disturbance coming out of Nebraska. Important note: there may only be a couple of hours in between each round.

The initial storm development with each round will involve discrete storms. Given the atmospheric profiles, the primary severe risks from the initial storms will be very large hail and tornadoes. Once the initial storms grow upscale into lines, the primary severe risk will shift to very damaging winds and spin-up tornadoes. The second round of storms will be aided by the strengthening LLJ late this afternoon and evening.

The CSU severe ML progs for Wednesday show this well; the tornado risk of 5 to 10% is mainly along/west of the Mississippi. Likewise, the hail risk is 15-30% mainly along/west of the Mississippi.

The damaging wind risk is 30-45%, but, has a 45-60% probability east of the Mississippi. This agrees with the scenario that the initial supercells will transition in to a QLCS roughly along the Mississippi.

That being said, precipitation loaded downdrafts would be capable of producing damaging winds of 60-70 mph. The sub-hour CAMs are suggesting there may be corridors of damaging winds of 70-80+ mph from the strongest storms.

Once the second round of storms clear the area, the remainder of the overnight hours look to be mainly quiet.

Thursday/Thursday night...

Thursday will be a near repeat of Wednesday.

The timing of the two rounds of storms may vary by an hour or two. A disturbance moving out of the Plains will initiate the first round roughly from 10 AM to 4 PM. The strong cold front and associated low looks to initiate round two from 3 to 10 PM.

The tornado risk looks to be higher for Thursday. The CSU severe ML progs and SPC have the 10% tornado risk for nearly all the area. The surface low associated with the cold front for the second round of storms may be when the tornado risk is the highest. Indeed, some CAMs are generating strong to very strong helicity tracks near the surface low in the discrete storm formation.

Thus very large hail and tornadoes would be seen during the initial discrete storm formation for each round on Thursday. Strong tornadoes would be possible with the second round of storms due to the surface low causing more backing of the surface winds and thus increasing the rotation going into storm updrafts.

Like Wednesday, the initial supercells will grow upscale into a QLCS with each round on Thursday; the severe risks would then transition to damaging winds and spin-up tornadoes. Damaging winds of 60-70 mph would be see with potential corridors of 70-80+ mph winds from the stronger storms.

An additional concern for Thursday will be the potential for flash flooding, especially if storms repeat over the same areas. The ground will be primed from the heavy rain on Wednesday so additional rounds of heavy rain Thursday would result in rapid runoff and potential flash flooding. Depending upon how storms evolve Wednesday, a flash flood watch for Thursday may need to be considered.

LONG TERM /FRIDAY THROUGH TUESDAY/

Issued at 219 AM CDT Wed Jun 10 2026

Friday...With the cold frontal passage Thursday night, the flow throughout the atmosphere becomes unidirectional out of the westerly as high pressure anchors to our south. Cold air advection is forecasted to push highs back down into the upper 70s with mostly clear skies.

Saturday...Pleasant conditions do not last long as another shortwave rotates into the Dakotas Saturday afternoon. A cold front attached to an occluded low pressure system south of Hudson bay will be pushed into Iowa as a secondary low pressure deepens over Kansas. This will brings PoPs back up around 40-60%. A little bit of deju vu from Thursday with warm and moist air advection in the low levels, but the limited time with the southerly flow should only permit a low-to-medium chance (30-50%) for SBCAPE to get above 1000 J/kg. Bulk shear is also expected to be weaker than Thursday at only 35-40 knots. Therefore, there is a marginal chance at severe storms, but nothing like Wednesday and Thursday.

Sunday-Monday...As northerly flow returns in the low levels post cold front, highs return back to the 70s on Sunday. There is some model uncertainty on cloud cover as some lingering mid-level moisture could manifest into an altostratus deck. Regardless, Sunday will likely (60-80%) be a dry one. Monday is more iffy though as a trough digs into the Northern Rockies, producing a Front Range low pressure and developing a warm front. PoPs on Monday will be dependent on the frontal place and a potential mid-level F-gen band. Highs have a good chance (80-90%) of once again being below 80 degrees as cool air and cloud cover stick around.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 613 AM CDT Wed Jun 10 2026

Convection is likely to impact terminals at times during the TAF period. The first round is expected roughly 16z-20z that will have the potential for pockets of severe wind (50+ kt) and hail. This was handled with TEMPO groups with IFR to lower MVFR ceilings and/or visibility and gusts sub-severe for now (40 kt) until confidence increases on favored corridor(s) for severe wind. Outside of the storms today, expect VFR conditions and gradient winds that could gust to 30 kt from the SSW. The second round of convection is expected in the late afternoon and evening (22z-04z) ahead of a cold front. This round could have some initial supercells with all hazards before evolving into a line(s) with damaging winds and an embedded tornado threat. Earlier convection likely will have an impact on greatest corridors for this threat and for this reason have maintained PROB30 mention for now. There could be a third round very late in the TAF period with an elevated LLJ atop any residual cool pools, but confidence on location is too low for any mention with these TAFs.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.